Multi-wavelength laser system for optical data communication links and associated methods

ABSTRACT

A laser light generator is configured to generate one or more wavelengths of continuous wave laser light. The laser light generator is configured to collectively and simultaneously transmit each of the wavelengths of continuous wave laser light through an optical output of the laser light generator as a laser light supply. An optical fiber is connected to receive the laser light supply from the optical output of the laser light generator. An optical distribution network has an optical input connected to receive the laser light supply from the optical fiber. The optical distribution network is configured to transmit the laser light supply to each of one or more optical transceivers and/or optical sensors. The laser light generator is physically separate from each of the one or more optical transceivers and/or optical sensors.

CLAIM OF PRIORITY

This application is a continuation application under 35 U.S.C. 120 ofprior U.S. application Ser. No. 15/277,968, filed Sep. 27, 2016, whichclaims priority under 35 U.S.C. 119(e) to U.S. Provisional PatentApplication No. 62/236,384, filed Oct. 2, 2015. The disclosure of eachabove-identified patent application is incorporated herein by referencein its entirety for all purposes.

BACKGROUND 1. Field of the Invention

The present invention relates to fiber-optic data communication.

2. Description of the Related Art

Multi-mode optical communication standards, such as the 100G-SR4standard of IEEE 802.3, rely upon direct-modulated laser sources thatare integrated within the transceiver module. For example, FIG. 1A showsa transceiver module 101 having a direct-modulated laser 103 integratedtherein. The direct-modulated laser 103 is turned on and off to producean on-off keyed light transmission at an output 104. The transceivermodule 101 also includes a receiver module 105 configured to receive anencoded light transmission at an input 106 for decoding. It should beunderstood that the direct-modulated laser 103 is implemented directlyand physically within the transceiver module 101.

Single-mode optical communication typically uses an indirect modulationscheme (though direct modulation is also possible) in which continuouswave light generated by a laser is modulated by a modulator. Forexample, FIG. 1B shows a transceiver module 107 having anindirect-modulated laser configuration in which a laser light source 109within the transceiver module 107 produces continuous wave light that ismodulated by an independent modulator 111 within the transceiver module107 to generate a light stream of encoded data for transmission at anoutput 112 of the transceiver module 107. The transceiver module alsoincludes a receiver module 113 configured to receive an encoded lighttransmission at an input 114 for decoding. It should be understood thatthe laser light source 109 is implemented directly and physically withinthe transceiver module 107.

In some configurations, a laser light source is shared across multipletransceivers within the same transceiver module, where transmitters ofthe multiple transceivers transmit at the same wavelength of light, suchas in accordance with optical communication specification 100G-PSM4 ofthe parallel single mode 4-lane multi-source agreement (PSM4 MSA) group.For example, FIG. 1C shows a laser light source 117 connected to providelaser light to multiple transceivers within a transceiver module 115.The multiple transceivers are defined by multiple modulators 119-1 to119-N and multiple receiver modules 121-1 to 121-N. The multiplemodulators 119-1 to 119-N are parts of respective transmitter modulesconfigured to generate multiple light streams of encoded data fortransmission at respective outputs 120-1 to 120-N of the transceivermodule 115. The laser light source 117 supplies continuous wave light tothe multiple independent modulators 119-1 to 119-N within the sametransceiver module 115 as the laser light source 117. The multiplereceiver modules 121-1 to 121-N are configured to receive encoded lighttransmissions at respective inputs 122-1 to 122-N for decoding. Itshould be understood that the laser light source 117 is implementeddirectly and physically within the transceiver module 115.

Wavelength division multiplexing (WDM) has been proposed to scalebandwidth per optical fiber in fiber-optic data communication systems,such as in accordance with optical communication standard 100G-LR4 ofIEEE 802.3). FIG. 1D shows a transceiver module 123 for WDM optical datacommunication in which multiple laser light sources 125-1 to 125-N areimplemented to respectively supply continuous wave light of differentwavelengths to multiple modulators 127-1 to 127-N of correspondingmultiple transmitters. Each of the multiple modulators 127-1 to 127-N isconfigured to generate a respective light stream of encoded data basedon the wavelength of the continuous wave light that it receives from itscorresponding laser light source 125-1 to 125-N. The multiple lightstreams of encoded data output by the multiple modulators 127-1 to 127-Nare multiplexed onto a single optical fiber in accordance with the WDMoptical data communication standard by a wavelength multiplexer 129 fortransmission at an output 130 of the transceiver module 123. Themultiple transmitters within the transceiver module 123 also includemultiple receiver modules 131-1 to 131-N configured to receive encodedlight transmissions for decoding from a wavelength demultiplexer 133.The wavelength demultiplexer 133 is configured to receive a transmissionof multiple light streams of encoded data that have been multiplexedonto a single optical fiber in accordance with the WDM optical datacommunication standard at an input 134, and supply separate ones of themultiple light streams of encoded data to corresponding ones of themultiple receiver modules 131-1 to 131-N for decoding. It should beunderstood that the multiple laser light sources 125-1 to 125-N areimplemented directly and physically within the transceiver module 123.

The laser light sources used for WDM optical data communication requireprecise temperature control due to wavelength drift of the laser lightsources with variation in temperature and due to the close spacing ofthe optical wavelength channels as defined by the WDM opticalcommunication standard. Such precise temperature control can be costly,bulky, and power-consuming. Therefore, WDM optical data communicationusing multiple laser light sources with precise temperature control canbe undesirable for shorter reach communication networks such as thenetworks present in data centers. Coarse wavelength divisionmultiplexing (CWDM) optical data communication, such as in accordancewith optical communication specification 100G-CWDM4 of the coarsewavelength division multiplexing 4-lane multi-source agreement (CWDM4MSA) group, relaxes the wavelength channel spacing requirements in orderto simplify the thermal control of the multiple laser light sources.

Both WDM and CDWM use multiple laser light sources that are directly andphysically implemented within the transceiver module to generate the setof wavelengths that are needed for the optical data communication. And,typical laser light sources implemented within the transceiver moduleare configured to output only 5 milliWatts (mW) to 10 mW of power.However, there are several drawbacks to having the laser light sourcesimplemented directly and physically within the transceiver module. Forexample, one such drawback is difficulty of replacement of the laserlight source. Within the optical data communication system, the laserlight source is the component that has the shortest mean time tofailure. Replacement of a malfunctioning/failed laser light sourcerequires replacement of the entire transceiver module, which islogistically difficult and costly.

Another drawback of having the laser light source implemented directlyand physically within the transceiver is that the laser light source,which is a thermally-sensitive component, is exposed to and musttolerate the same range of temperature variation as the othertransceiver components. This exacerbates the aforementioned issueregarding precise temperature control of the laser light sources due towavelength drift caused by variation in temperature. Additionally, whenthe laser light source is implemented directly and physically within thetransceiver, the laser light source is confined within the small formfactor of the transceiver which makes thermal dissipation moredifficult, thereby lowering the efficiency and reliability of the laserlight source.

Another drawback of having the laser light source implemented directlyand physically within the transceiver is that the laser light source isoperated at relatively low power (enough to power a single link), whichcan adversely affect wall-plug efficiency. Also, there are form factorand material constraints associated with integration of the laser lightsource within the transceiver module. Another drawback of having thelaser light source implemented directly and physically within thetransceiver is that the power budget of the laser light source adds tothe power budget of the transceiver module, which compounds the powerdissipation problem faced by small form factor transceiver modules.

Also, as disclosed in U.S. Pat. No. 7,715,714, use of a centralizedlaser power grid having an array of single-wavelength continuous wavelaser light sources in a packet-switched optical network has beenconsidered. However, such methods that implement the centralized laserpower grid use wavelength-addressable switches to steer continuous wavelaser power to specific optical links, which results in an architecturethat is significantly different than that of the inventive embodimentsdisclosed herein with regard to the present invention. It is within thiscontext that the present invention arises.

SUMMARY

In an example embodiment, a laser light supply system for fiber-opticdata communication is disclosed. The laser light supply system includesa laser light generator configured to simultaneously generate one ormore wavelengths of continuous wave laser light. The laser lightgenerator has an optical output. The laser light generator is configuredto transmit each of the one or more wavelengths of continuous wave laserlight through the optical output as a laser light supply. The laserlight supply system also includes an optical conveyance device connectedto receive the laser light supply from the optical output of the laserlight generator. The laser light supply system also includes an opticaldistribution network having an optical input connected to the opticalconveyance device to receive the laser light supply from the laser lightgenerator. The optical distribution network is configured to transmitthe laser light supply to each of one or more optical transceivers. Thelaser light generator is physically separate from each of the one ormore optical transceivers.

In an example embodiment, a method is disclosed for supplying laserlight for fiber-optic data communication. The method includes generatingmultiple wavelengths of continuous wave laser light at a locationphysically separate from one or more optical transceivers that utilizethe multiple wavelengths of continuous wave laser light for encodingdata. The method also includes transmitting each of the multiplewavelengths of continuous wave laser light in a collective andsimultaneous manner through an optical distribution network to the oneor more optical transceivers. The method also includes receiving themultiple wavelengths of continuous wave laser light at the one or moreoptical transceivers. The method also includes using one or more of themultiple wavelengths of continuous wave laser light received at the oneor more optical transceivers to encode data into one or more data lightstreams.

In an example embodiment, a laser light supply system for opticalsensing is disclosed. The laser light supply system includes a laserlight generator configured to simultaneously generate one or morewavelengths of continuous wave laser light. The laser light generatorhas an optical output. The laser light generator is configured totransmit each of the one or more wavelengths of continuous wave laserlight through the optical output as a laser light supply. The laserlight supply system includes an optical conveyance device connected toreceive the laser light supply from the optical output of the laserlight generator. The laser light supply system also includes an opticaldistribution network having an optical input connected to the opticalconveyance device to receive the laser light supply from the laser lightgenerator. The optical distribution network is configured to transmitthe laser light supply to each of one or more optical sensors. The laserlight generator is physically separate from each of the one or moreoptical sensors.

Other aspects and advantages of the invention will become more apparentfrom the following detailed description, taken in conjunction with theaccompanying drawings, illustrating by way of example the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a transceiver module having a direct-modulated laserconfiguration.

FIG. 1B shows a transceiver module having an indirect-modulated laserconfiguration.

FIG. 1C shows a laser light source connected to provide laser light tomultiple transceivers within a transceiver module.

FIG. 1D shows a transceiver module for WDM optical data communication.

FIG. 2 shows an example architecture of a transceiver module for usewith a remotely located (physically separate) laser light supply system,in accordance with some embodiments of the present invention.

FIG. 3 shows an example architecture of a laser light supply system forfiber-optic data communication, in accordance with some embodiments ofthe present invention.

FIG. 4 shows the laser light supply system with an example architectureof the optical distribution network, in accordance with some embodimentsof the present invention.

FIG. 5A shows a laser light generator that combines the laser lightoutput of multiple single-wavelength continuous wave lasers onto anoptical conveyance device, in accordance with some embodiments of thepresent invention.

FIG. 5B shows a laser light generator that combines the laser lightoutput of multiple single-wavelength continuous wave lasers ontomultiple optical conveyance devices, in accordance with some embodimentsof the present invention.

FIG. 6 shows an example diagram of the optical add/drop comb filter, inaccordance with some embodiments of the present invention.

FIG. 7 shows a laser light generator that couples together the laserlight output of multiple single-wavelength continuous wave lasers andoutputs all of the multiple wavelengths of laser light onto each ofmultiple optical conveyance devices, in accordance with some embodimentsof the present invention.

FIG. 8 shows the multiple lasers of the set of lasers mounted on acommon (shared) thermally conductive substrate, in accordance with someembodiments of the present invention.

FIG. 9 shows the laser light supply system mounted within a server rackas a rack unit within a data center, in accordance with some embodimentsof the present invention.

FIG. 10 shows the laser light supply system mounted inside a fabricswitch in a data center, in accordance with some embodiments of thepresent invention.

FIG. 11 shows a number of laser light supply systems placed in adedicated laser supply rack/cabinet in a data center, in accordance withsome embodiments of the present invention.

FIG. 12 shows a flowchart of a method for supplying laser light forfiber-optic data communication, in accordance with some embodiments ofthe present invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art that the presentinvention may be practiced without some or all of these specificdetails. In other instances, well known process operations have not beendescribed in detail in order not to unnecessarily obscure the presentinvention.

Systems and methods are disclosed herein for improving fiber-optic datacommunication. More specifically, systems and methods are disclosedherein for a high-powered multi-wavelength laser light supply system foruse in fiber-optic data communication. Also, various embodiments aredisclosed herein for fiber-optic data communication systems andassociated methods in which the laser light supply system is implementedseparate, i.e., physically separate, from transceivers that use thelaser light provided by the laser light supply system. Separation of thetransceiver modules from the laser light source has multiple benefits,including decoupling of failure modes, heat management, serviceability,and upgradeability, among others. Another advantage of having the laserlight source separate and independent from the transceiver module is thesimplicity of the transceiver module's optical package, as no laseralignment step is required in the transceiver module itself, and theoptical packaging step for the transceiver module simply requiresconnection of an optical fiber to the transceiver module's opticalinput. Additionally, the laser light source outputs continuous wavelaser light and does not require an electrical package with high-speedinput/output (I/O).

In some embodiments, the laser light supply system disclosed herein isconfigured to supply continuous wave laser light of multiple wavelengthsto multiple dense wavelength division multiplexed (DWDM) optical linksin fiber-optic data communication systems. However, it should beunderstood that in some embodiments, the laser light supply systemdisclosed here can be used to supply continuous wave laser light ofmultiple wavelengths to other types of optical links, i.e., to non-DWDMoptical links. The continuous wave laser light output by the laser lightsupply system can be modulated by transmitters within the optical links.And, the modulated light can then be received and processed by receiversof the optical links. The transmitters and receivers together form thetransceivers of the optical links.

FIG. 2 shows an example architecture of a transceiver module 201 for usewith a remotely located (physically separate) laser light supply system,in accordance with some embodiments of the present invention. Thetransceiver module 201 includes a number (N) of transceivers 203-1 to203-N. The transceivers 203-1 to 203-N include transmitters 205-1 to205-N and receivers 207-1 to 207-N, respectively. Each transmitter 205-1to 205-N has an optical input 204-1 to 204-N, respectively, throughwhich continuous wave laser light is received from the remotely locatedlaser light supply system. In some embodiments, continuous wave laserlight is transmitted from the remotely located laser light supply systemto the optical inputs 204-1 to 204-N of the transmitters 205-1 to 205-Nthrough optical conveyance devices. It should be understood that theterm “optical conveyance device” as used herein can refer to an opticalfiber, or an optical waveguide, or any other type of device configuredto convey photons from one location to another location. Eachtransceiver 203-1 to 203-N is configured to convert a data signalbetween the optical and electrical domains. The transmitters 205-1 to205-N convert a data signal from the electrical domain to the opticaldomain. And, the receivers 207-1 to 207-N convert a data signal from theoptical domain to the electrical domain.

Each transmitter 205-1 to 205-N is configured to modulate the lightreceived through its optical input from the remotely located laser lightsupply system to generate a light stream of encoded data. Eachtransmitter 205-1 to 205-N is also configured to transmit the lightstream of encoded data through an optical output 206-1 to 206-N,respectively. In some embodiments, optical conveyance devices areoptically connected to the optical outputs 206-1 to 206-N of thetransmitters 205-1 to 205-N for conveyance of the light streams ofencoded data to other downstream devices. The receivers 207-1 to 207-Nare configured and connected to receive modulated light throughrespective optical inputs 208-1 to 208-N. The received modulated lightrepresents a light stream of encoded data. The receivers 207-1 to 207-Nare also configured to decode the modulated light from the opticaldomain into the electrical domain, in which the data is represented byelectrical signals. In some embodiments, the transceivers referred toherein are DWDM transceivers configured to operate according to theInternational Telecommunication Union's TelecommunicationStandardization Sector (ITU-T). However, in other embodiments, thetransceivers referred to herein can operate in a different wavelengthrange or be non-DWDM transceivers.

FIG. 3 shows an example architecture of a laser light supply system 301for fiber-optic data communication, in accordance with some embodimentsof the present invention. The laser light supply system 301 includes alaser light generator 303 configured to simultaneously generate multiplewavelengths of continuous wave laser light. The laser light generator303 has an optical output. The laser light generator 303 is configuredto collectively and simultaneously transmit each of the multiplewavelengths (λ1-λN) of continuous wave laser light through the opticaloutput as a laser light supply. The laser light supply system 301 alsoincludes an optical conveyance device 305 connected to receive the laserlight supply from the optical output of the laser light generator 303.It should be understood that the laser light generator 303 operates toproduce and transmit N different wavelengths of light (Xi to XN) on theoptical conveyance device 305 simultaneously. In some embodiments, theoptical conveyance device 305 is a single-mode optical fiber.

The laser light supply system 301 also includes an optical distributionnetwork 307 having an optical input connected to receive the laser lightsupply from the optical conveyance device 305. The optical distributionnetwork 307 is configured to transmit, i.e., fan out, the laser lightsupply to each of one or more optical transceivers 311-1 to 311-N. Insome embodiments, the optical distribution network 307 includes anoptical splitter network configured to split (fan-out) the total laserlight power output by the laser light generator 303 to supply laserlight to multiple optical links, such as to multiple DWDM links. In someembodiments, the optical distribution network 307 uses opticalconveyance devices to guide the laser light from the output of the laserlight generator 303 to the various optical links. For example, FIG. 3shows that the laser light supply is transmitted through opticalconveyance devices 309-1 to 309-N to the optical transceivers 311-1 to311-N, respectively. In some embodiments, the optical conveyance devices309-1 to 309-N are single-mode optical fibers. Therefore, each of theoptical transceivers 311-1 to 311-N receives each of the multiplewavelengths (Xi-XN) of continuous wave laser light in a simultaneousmanner through its respective one of the optical conveyance devices309-1 to 309-N.

It should be understood that the laser light generator 303 is physicallyseparate from each of the one or more optical transceivers 311-1 to311-N. In various embodiments, the generated continuous wave multiplewavelength (λ₁-λ_(N)) laser light can be split among several opticalconveyance devices, and may or may not be amplified before or aftersplitting, as the continuous wave laser light of the multiplewavelengths (λ₁-λ_(N)) is distributed for use at multiple locations,such as at multiple transceiver locations within a data center. Forexample, in some embodiments, passive and/or active optical powersplitters can be provided in the light distribution paths of the opticaldistribution network 307 to provide for the splitting (fanning-out) ofthe total laser light power output by the laser light generator 303 tothe various optical links.

In some embodiments, the optical distribution network 307 itself isdistributed, with various optical components implemented onoptical-electrical devices (such as silicon-photonic chips or othertypes of devices) using passive waveguide couplers and optical filtersand/or external optical components such as fused-fiber optical couplersand optical splitters. The optical splitter network of the opticaldistribution network 307 can include active optical components. Forexample, in some embodiments, optical amplifiers can be inserted in theoptical distribution network 307 to mitigate laser light losses duringdistribution and/or to lower the laser light output power requirement ofthe laser light generator 303. It should be understood that in variousembodiments the optical amplifiers referred to herein can be configuredas either semiconductor optical amplifiers (SOAs), erbium-doped fiberamplifiers (EDFAs), ytterbium-doped fiber amplifiers (YDFAs), taperedamplifier (TAs), and/or other types of optical amplifiers. In someembodiments, when optical amplifiers are used to lower the laser lightoutput power requirement of the laser light generator 303, the laserlight generator 303 can essentially function as a wavelength reference.In these embodiments, the laser light generator 303 is responsible forproducing laser light at each of the multiple wavelengths (λ₁-λ_(N)),and the optical distribution network 307 is responsible for amplifyingand distributing the laser light power at each of the multiplewavelengths to the levels needed for the transceiver modules 311-1 to311-N.

As an example of the amount of laser power output by the laser lightsupply system 301, consider a top-of-rack (TOR) switch with an aggregate5 terabits per second (Tb/s) of bandwidth that uses DWDM transceiverstransmitting at 10 gigabits per second (Gb/s) per wavelength channel. Atthis data rate, the DWDM transceiver requires 1 mW of laser power oneach wavelength channel. Under these conditions, the laser light supplysystem 301 would need to supply 500 mW of total laser power to the TORswitch in order to meet the total laser power requirement.

It should be understood that the laser light supply system 301 includesa continuous wave laser light source (the laser light generator 303) anda passive and/or active optical splitter/amplifier network (opticaldistribution network 307) for distribution of the laser power tomultiple optical links. In some embodiments, the laser light supplysystem 301 can also include redundant laser light sources for backup inthe case of failure of a laser light source. In some embodiments, thelaser light supply system 301 uses optical conveyance devices tooptically connect various optical components together through theirrespective optical ports. In some embodiments, the laser light supplysystem 301 uses single-mode optical fibers. In some embodiments, thelaser light supply system 301 uses polarization-maintaining single-modeoptical fibers in conjunction with polarization sensitive components,such as optical amplifiers, optical isolators, and/or opticaltransceivers.

FIG. 4 shows the laser light supply system 301 with an examplearchitecture of the optical distribution network 307, in accordance withsome embodiments of the present invention. The optical distributionnetwork 307 is configured to power-split the laser light supply receivedfrom the laser light generator 303 into multiple optical conveyancedevices through optical couplers and/or optical splitters. Also, opticalamplifiers are disposed within the optical distribution network 307 toenable a larger number of transceiver endpoints, and to allow forpotentially less power in the laser light supply provided by the laserlight generator 303.

It should be understood that the architecture of the opticaldistribution network 307 as shown in FIG. 4 is provided as an examplefor description purposes. In different embodiments, the opticaldistribution network 307 can include essentially any arrangement ofoptical couplers, optical splitters, and optical amplifiers, as well asother optical components, as needed to distribute the laser light supplyprovided by the laser light generator 303 to each of multipletransceivers.

In the example of FIG. 4, the laser light supply provided by the laserlight generator 303 is received into an optical splitter 401. Theoptical splitter is configured to transmit a first portion of theincoming laser light onto an optical conveyance device 403 and transmita second portion of the incoming laser light onto an optical conveyancedevice 415. The optical conveyance device 403 is connected to an opticalamplifier 405, which is configured to amplify the power of the light itreceives from the optical conveyance device 403 without changing itswavelength(s). Similarly, the optical conveyance device 415 is connectedto an optical amplifier 417, which is configured to amplify the power ofthe light it receives from the optical conveyance device 415 withoutchanging its wavelength(s). The light output from the optical amplifier405 is transmitted through an optical conveyance device 407 to anotheroptical splitter 409, which is configured to split the light it receivesonto two additional optical conveyance devices 411 and 413. And,similarly, the light output from the optical amplifier 417 istransmitted through an optical conveyance device 419 to another opticalsplitter 421, which is configured to split the light it receives ontotwo additional optical conveyance devices 423 and 425. It should beunderstood that the optical distribution network 307 can include as manyoptical devices as needed to duplicate and transmit the laser lightsupply as provided by the laser light generator 303 onto as many opticalconveyance devices as there are transceivers (or other components) to besupplied with the laser light supply.

Additionally, the transceiver modules, such as transceiver module 201,can also include optical couplers, optical splitters, and opticalamplifiers, as well as other optical components, as needed toappropriately distribute the laser light supply received at the opticalinput of the transceiver module to the various transceivers within thetransceiver module. For example, FIG. 4 shows a transceiver module 427that receives the incoming laser light supply into an optical splitter429. The optical splitter 429 is configured to transmit a first portionof the incoming laser light onto an optical conveyance device 431 andtransmit a second portion of the incoming laser light onto an opticalconveyance device 443. The optical conveyance device 431 is connected toanother optical splitter 433 which is configured to transmit a portionof the incoming laser light onto an optical conveyance device 435 andtransmit another portion of the incoming laser light onto an opticalconveyance device 439. The optical conveyance device 435 is connected tothe optical input of a transceiver 437, so that the laser light supplytransmitted through the optical conveyance device 435 is provided to thetransceiver 437. Also, the optical conveyance device 439 is connected tothe optical input of a transceiver 441, so that the laser light supplytransmitted through the optical conveyance device 439 is provided to thetransceiver 441.

Similarly, the optical conveyance device 443 is connected to anotheroptical splitter 445 which is configured to transmit a portion of theincoming laser light onto an optical conveyance device 447 and transmitanother portion of the incoming laser light onto an optical conveyancedevice 451. The optical conveyance device 447 is connected to theoptical input of a transceiver 449, so that the laser light supplytransmitted through the optical conveyance device 447 is provided to thetransceiver 449. Also, the optical conveyance device 451 is connected tothe optical input of a transceiver 453, so that the laser light supplytransmitted through the optical conveyance device 451 is provided to thetransceiver 453. It should be understood that the transceiver module 427can include as many optical devices as needed to split/divide andtransmit the laser light supply as provided by the laser light generator303 onto as many optical conveyance devices as there are transceivers tobe supplied with the laser light supply.

It should also be understood that the laser light supplied to each ofthe transceivers 437, 441, 449, and 453 includes each of the multiplewavelengths (λ₁-λ_(N)) of continuous wave laser light as generated bythe laser light generator 303. Also, in some embodiments, variousoptical components (optical splitters, optical couplers, opticalamplifiers, etc.) within the optical distribution network 307 and/ortransceiver module(s) 427 can be implemented within one or moreoptical-electrical devices (such as silicon-photonic chips or othertypes of semiconductor chips formed of a III-V material) and/or asdiscrete components. For example, an optical amplifier can be integratedin a hybrid manner within a silicon-photonic chip or can be placedbetween optical-electrical devices. This may be particularly useful forfinal stage optical power splitting and distribution. It should beunderstood that both an optical-electrical device, e.g.,silicon-photonic chip, and a transceiver module can include multipleindividual transceivers.

The laser light generator 303 can be configured in different ways invarious embodiments. In some embodiments, the laser light generator 303is configured using a comb laser to generate multiple wavelengths oflaser light (Xi to XN) for transmission on the optical conveyance device305. Also, in some embodiments, the laser light generator 303 isconfigured using separate lasers to generate each wavelength of laserlight (λ₁ to λ_(N)), and is further configured to combine the multiplewavelengths of laser light (λ₁ to λ_(N)) for transmission through one ormore optical conveyance devices.

The comb laser includes a single laser that has a single lasing cavitywhich is used to produce all of the multiple laser light wavelengths (λ₁to λ_(N)) in a wavelength comb spectrum. In some embodiments, thewavelengths in the wavelength comb spectrum correspond to thewavelengths required by the DWDM optical links that are supplied withlaser light by the laser light supply system 301. The comb laser canhave one or more optical outputs. In the case of multiple opticaloutputs, the same set of laser light wavelengths (λ₁ to λ_(N)) aresupplied at each optical output of the comb laser. In some embodiments,the comb laser does not need to be a high-power output laser. Morespecifically, the comb laser can provide a low-power laser light output,and this low-power laser light output can be amplified using one or moreoptical amplifiers in order to increase the total laser light outputpower of the laser light supply system 301. It should be understood thatin order to protect active optical components within the laser lightsupply system 301, such as the comb laser for example, fiber-opticisolators can be inserted at the optical inputs and/or optical outputsof the active optical components, if appropriate optical isolationcapability is not already included within the active optical componentsthemselves.

If the transceivers have innate wavelength-locking capability, such aswith DWDM transceivers, the wavelengths output by the laser lightgenerator 303 do not need to be constant and thermally-stable, so longas the changes in wavelength are within the wavelength-locking range ofthe transceivers, and so long as the wavelength channel spacing ismaintained to meet minimum channel-to-channel separation specifications.With the laser light generator 303 implemented as the single cavity comblaser, the wavelength channel spacing requirement is guaranteed.However, the comb laser should have a thermal mode-hop-free range thatis equivalent to the range of temperature fluctuations experienced bythe laser light generator 303.

In some embodiments, instead of using the comb laser, the laser lightgenerator 303 is implemented as a set of lasers, with each laser in theset of lasers producing a single wavelength of light of some specifiedsubset of wavelengths of light. The outputs of the multiple lasers inthe set of lasers are combined in an optical combiner network to form awavelength comb spectrum using passive and/or active optical components.Also, the total combined laser light power output by the opticalcombiner network is supplied to the optical distribution network 307 onone or more optical conveyance devices 305.

FIG. 5A shows a laser light generator 303A that combines the laser lightoutput of multiple (N) single-wavelength continuous wave lasers onto anoptical conveyance device 511, in accordance with some embodiments ofthe present invention. It should be understood that the laser lightgenerator 303A is an embodiment of the laser light generator 303. Thelaser light generator 303A includes a set of lasers 501. The set oflasers 501 includes multiple (N) lasers 501-1 to 501-N. Each laser 501-1to 501-N is configured to generate continuous wave laser light at adifferent wavelength, such that the lasers 501-1 to 501-N generate laserlight wavelengths λ₁ to λ_(N), respectively. The laser light generator303A also includes a set of optical conveyance devices, which includesoptical conveyance devices 503-1 to 503-N, which respectively correspondto the lasers 501-1 to 501-N in the set of lasers 501. Each opticalconveyance device 503-1 to 503-N in the set of optical conveyancedevices is connected to receive the continuous wave laser lightgenerated by its corresponding laser 501-1 to 501-N in the set of lasers501. In some embodiments, the optical conveyance devices 503-1 to 503-Ncan be optical waveguides, optical fibers, or other types of opticalconveyance devices. In some embodiments, the optical conveyance devices503-1 to 503-N are single-mode optical fibers.

The laser light generator 303A also includes an optical add/drop combfilter 505 having a set of optical inputs respectively connected to theoptical conveyance devices 503-1 to 503-N, such that the opticaladd/drop comb filter 505 is connected to separately receive thecontinuous wave laser light at the different wavelength as generated byeach laser 501-1 to 501-N of the set of lasers 501. The optical add/dropcomb filter 505 is configured to combine the continuous wave laser lightat the different wavelength as generated by each laser 501-1 to 501-N ofthe set of lasers 501 together onto a common optical conveyance devicethat is optically connected to an optical output of the optical add/dropcomb filter 505. The laser light generator 303A of FIG. 5A represents anN-channel combiner network implemented using the optical add/drop combfilter 505. In various embodiments, the optical add/drop comb filter 505can be implemented using an N-channel arrayed waveguide grating (AWG),echelle gratings, or as a bank of N microring resonators with separatedrop ports. In various embodiments, some components of the laser lightgenerator 303A can be implemented on silicon-photonic chips orexternally.

FIG. 6 shows an example diagram of the optical add/drop comb filter 505,in accordance with some embodiments of the present invention. Theoptical add/drop comb filter 505 is implemented using a bank ofsilicon-photonic microring resonator devices 106-1 to 106-N. Thecontinuous wave laser light output by each laser 503-1 to 503-N entersthe optical add/drop comb filter 505 through a different optical port603-1 to 603-N, respectively, and gets added together on a commonoptical conveyance device 605. The common optical conveyance device 605is optically connected to an optical output 609 of the optical add/dropcomb filter 505, which is in turn optically connected to an opticalconveyance device 507. In this manner, the multiple wavelengths(λ₁-λ_(N)) of laser light generated by the set of lasers 501 arecombined together on the common optical conveyance device 605, and aretransmitted together through the optical conveyance device 507. In someembodiments, the optical conveyance device 507 is a single-mode opticalfiber. In some embodiments, the optical add/drop comb filter 505 isconfigured to provide selection control over which of the differentwavelengths (λ₁-λ_(N)) of continuous wave laser light as generated bythe set of lasers 501 are combined together on the common opticalconveyance device 605.

The optical conveyance device 507 is connected to receive lighttransmitted from the optical output 609 of the optical add/drop combfilter 505. In some embodiments, an optical amplifier 509 can beoptionally used at the output of the laser light generator 303A tocompensate for light losses in distribution. When used, an optical inputof the optical amplifier 509 is optically connected to receive lightfrom the optical conveyance device 507. The optical amplifier 509 isconfigured to amplify each wavelength of light (λ₁-λ_(N)) received atits optical input to generate amplified light. The optical amplifier 509is configured to transmit the amplified light as the laser light supplyto the optical output of the laser light generator 303A and onto theoptical conveyance device 511. In some embodiments where the opticalamplifier 509 is not used, the optical output 609 of the opticaladd/drop comb filter 505 is optically connected to the optical output ofthe laser light generator 303A and onto the optical conveyance device511.

FIG. 5B shows a laser light generator 303A-1 that combines the laserlight output of multiple (N) single-wavelength continuous wave lasersonto multiple optical conveyance devices 511-1 through 511-x, inaccordance with some embodiments of the present invention. It should beunderstood that the laser light generator 303A-1 is an embodiment of thelaser light generator 303. The laser light generator 303A-1 includes anoptical splitter/amplifier network 513 optically connected to receivelight from the optical conveyance device 507. The opticalsplitter/amplifier network 513 is configured to split, and if necessaryamplify, each wavelength of light (λ₁-λ_(N)) received at its opticalinput in order to transmit each wavelength of light (λ₁-λ_(N)) as thelaser light supply to each of the multiple optical conveyance devices511-1 through 511-x.

It should be understood that the laser light generator 303A-1 includesthe optical splitter network 513 which has an optical input opticallyconnected to receive the light transmitted through the common opticalconveyance device 507. The laser light generator 303A-1 has multipleoptical outputs. The optical splitter network 513 is configured to splitthe light received through its optical input onto the multiple opticalconveyance devices 511-1 through 511-x, such that each of the one ormore wavelengths (λ₁-λ_(N)) of continuous wave laser light is providedas the laser light supply to each of the multiple optical outputs of thelaser light generator 303A-1.

FIG. 7 shows a laser light generator 303B that couples together thelaser light output of multiple (N) single-wavelength continuous wavelasers and outputs all of the multiple wavelengths of laser light ontoeach of multiple optical conveyance devices 707-1 to 707-N, inaccordance with some embodiments of the present invention. It should beunderstood that the laser light generator 303B is an embodiment of thelaser light generator 303. The laser light generator 303B includes theset of lasers 501, including the multiple (N) lasers 501-1 to 501-N, asdescribed with regard to FIG. 5A. The laser light generator 303Bincludes an optical coupler network 701 having a set of optical inputsrespectively connected to the set of optical conveyance devices 503-1 to503-N such that the optical coupler network 701 is connected toseparately receive the continuous wave laser light at the differentwavelength as generated by each laser 501-1 to 501-N of the set oflasers 501.

The optical coupler network 701 is configured to combine the continuouswave laser light at the different wavelength as generated by each laser501-1 to 501-N of the set of lasers 501 together onto each of multipleoptical conveyance devices, such that each of the multiple opticalconveyance devices is connected to receive all of the differentwavelengths (λ₁-λ_(N)) of continuous wave laser light generated by theset of lasers 501. Each of the multiple optical conveyance deviceswithin the optical coupler network 701 is optically connected to arespective one of multiple optical outputs of the optical couplernetwork 701, which are respectively optically connected to opticalconveyance devices 703-1 to 703-N of a second set of optical conveyancedevices.

The laser light generator 303B includes a set of optical amplifiers705-1 to 705-N. Each optical conveyance device 703-1 to 703-N in thesecond set of optical conveyance devices is optically connected to anoptical input of a different optical amplifier 705-1 to 705-N in the setof optical amplifiers. Each optical amplifier 705-1 to 705-N in the setof optical amplifiers is configured to amplify each wavelength of lightreceived at its optical input to generate amplified light. Each opticalamplifier 705-1 to 705-N in the set of optical amplifiers is configuredto transmit the amplified light as the laser light supply to a differentone of multiple optical outputs 707-1 to 707-N of the laser lightgenerator 303B.

The laser light generator 303B of FIG. 7 represents an N-channelcombiner network implemented using the optical coupler network 701configured to couple the N wavelengths together and output all combinedN wavelengths of light on 1 to N optical conveyance devices. In someembodiments, the optical coupler network 701 is configured as a staroptical coupler, i.e., an N-input to N-output optical coupler. In theembodiments in which the laser light generator 303B has multiple opticalconveyance device outputs 707-1 to 707-N, each optical conveyance deviceoutput 707-1 to 707-N can be routed to a different destination and canbe amplified as needed. In various embodiments, some components of thelaser light generator 303B can be implemented on silicon-photonic chipsor externally.

In some embodiments in which the laser light generator 303 isimplemented using the set of lasers 501, the lasers 501-1 to 501-N aremounted on a shared, highly-thermally-conductive substrate, such thatall lasers 501-1 to 501-N experience the same thermal variations. Inthese embodiments, because the output wavelength of a given laser 501-1to 501-N is affected by the temperature of the laser, when all thelasers 501-1 to 501-N are mounted on the same substrate so as toexperience the same thermal variation, the output wavelengths of thedifferent lasers 501-1 to 501-N will move together to ensure aconsistent wavelength channel spacing in the output of the laser lightgenerator 303. In these embodiments, because the lasers 501-1 to 501-Nare thermally coupled, the lasers 501-1 to 501-N can be operated in anuncooled manner and can be allowed to drift together (with regard towavelength) with changes in system temperature. This drift in wavelengthcan be tracked by the wavelength-locking circuitry implemented withinthe transmitters and receivers of the optical link, such as the DWDMlink.

FIG. 8 shows the multiple lasers 501-1 to 501-N of the set of lasers 501mounted on a common (shared) thermally conductive substrate 801, inaccordance with some embodiments of the present invention. The commonthermally conductive substrate 801 is configured to distribute heatemanating from each laser 501-1 to 501-N in the set of lasers 501. Inthis manner, the thermally conductive substrate 801 acts as a heatspreader so as to equalize the temperatures of all lasers 501-1 to 501-Nmounted on the substrate 801.

In some embodiments, the optical transceivers 311-1 to 311-N areconfigured as dense wavelength division multiplexer (DWDM) transceivers,and as such the optical transceivers 311-1 to 311-N are configured tooperate in a wavelength tracking mode. In other words, the opticaltransceivers 311-1 to 311-N can continue to operate correctly even withdrift in the wavelength of the laser light supplied to it by the laserlight generator 303. However, with each of the multiple lasers 501-1 to501-N operating to supply a different wavelength of laser light, it isnecessary for the relative spacing between the different wavelengthsgenerated by the multiple lasers 501-1 to 501-N to remain substantiallyconstant.

Most drift in laser light wavelength is caused by variation intemperature of the laser. By having all of the multiple lasers 501-1 to501-N maintain a substantially same temperature, due to the multiplelasers 501-1 to 501-N being mounted to the common thermally conductivesubstrate 801, even as the substantially same temperature of themultiple lasers 501-1 to 501-N varies, the relative spacing between thedifferent wavelengths generated by the multiple lasers 501-1 to 501-Nwill remain substantially constant and trackable by the DWDMtransceivers. Also, it should be appreciated that in the embodiments inwhich the multiple lasers 501-1 to 501-N are mounted to the commonthermally conductive substrate 801 and supply laser light to wavelengthtracking transceivers (such as DWDM transceivers), the multiple lasers501-1 to 501-N can be configured without active temperature control. Forexample, in some embodiments, an optical communication link/system caninclude the laser light generator 303 having a configuration that isuncooled and not wavelength controlled, allowing the wavelengths oflaser light to drift in time, with the laser light generator 303implemented in conjunction with optical transceivers that havecontinuous wavelength tracking capability. For example, use ofmode-hop-free lasers 501-1 to 501-N mounted on the common thermallyconductive substrate 801 in combination with use of wavelength-lockingDWDM optical links eliminates the need for precise temperature controlof the components in the laser light generator 303, which reducescomplexity and saves cost.

In some embodiments, the laser light supply system 301 disclosed hereinis deployed and operated to supply laser light to transceivers locatedin several locations within a data center. The transceivers within thedata center can be located next to electrical switches (either on-boardthe switches or off-board the switches), and/or next to networkinterface cards (NICs) (either on-board the NICs or off-board the NICs),and/or next to electrical computing components such as centralprocessing units (CPUs), graphics processing units (GPUs), memorydevices, among other types of computing components. In some embodiments,the transceivers within the data center can be standalone componentsdisposed either on-board or off-board other electrical components. Insome embodiments, the transceivers within the data center can be on thesame semiconductor chips as the switch, NIC, or other computingcomponents. It should be understood that the transceivers used inconjunction with the laser light supply system 301 disclosed herein donot generate laser light themselves. Rather, each transceiver isconfigured to receive a supply of multiple-wavelength continuous wavelaser light through an optical conveyance device that is opticallyconnected between itself and the laser light supply system 301. Thetransceivers modulate the continuous wave laser light to imprint thedata to be transmitted into a data light stream. The modulated laserlight, i.e., the data light stream, enters another optical conveyancedevice, which delivers the modulated laser light to another locationwhere the modulated laser light is optically received, such as byanother transceiver.

In some embodiments, the transceivers are connected to serve data centerswitches. In these embodiments, the laser light supply system 301 islocated either in the switch box as a module, or on a shelf in the samerack as the switch, or is located in a dedicated rack or cabinet. Insome embodiments, the dedicated rack or cabinet has the sole purpose ofgenerating and supplying laser light power to transceivers in one ormore switches in the data center. Also, in some embodiments, thetransceivers are located next to NICs or computing components. In someof these embodiments, the laser light supply system 301 is located onone shelf in a rack of the data center, and the laser light supplysystem 301 is connected to supply laser light to components in multipleshelves of the same rack. Also, in some of these embodiments, the laserlight supply system 301 is located in a centralized cabinet thatsupplies light to multiple transceivers in multiple racks.

It should be understood that physically separating the laser lightsupply system 301 from the transceivers enables placement of the laserlight supply system 301 away from areas of large temperature variation(such as exist in the vicinity of switch chips, CPUs/GPUs, NICs, etc.),thereby improving laser power-efficiency and reliability. Separating thelaser light supply system 301 from the transceivers also enablesaccessibility to the laser light sources, e.g., to lasers 501-1 to501-N, for maintenance and replacement. And, separating the laser lightsupply system 301 from the transceivers enables supply of continuouswave laser light to multiple transceivers using a single laser lightsupply system 301.

FIG. 9 shows the laser light supply system 301 mounted within a serverrack 901 as a rack unit within a data center, in accordance with someembodiments of the present invention. The laser light supply system 301is optically connected to supply continuous wave laser power to alloptical transceivers in the rack 901. For example, the laser lightsupply system 301 is optically connected to supply laser power totransceivers 909-1 to 909-N in a top-of-rack switch 903 by way ofoptical connections 907-1 to 907-N, respectively. The top-of-rack switch903 includes switch 905. The laser light supply system 301 is alsooptically connected to supply continuous wave laser power to individualNICs connected to server rack units 913-1 to 913-N by way of opticalconnections 915-1 to 915-N, respectively. The server rack units 913-1 to913-N have corresponding transceivers 917-1 to 917-N. Each of thetransceivers 909-1 to 909-N and 917-1 to 917-N has an optical outputthrough which its transmitter can transmit an optical data stream and anoptical input through which its receiver can receive an optical datastream. Some transceivers can be connected to send and/or receiveoptical data streams to/from other components outside of the server rack901, such as indicated by optical communication links 911-1 and 911-2.And, some transceivers can be connected to send and/or receive opticaldata streams to/from other transceivers within the server rack 901, suchas indicated by optical communication links 919-1 and 919-N.

FIG. 10 shows the laser light supply system 301 mounted inside a fabricswitch 1001 in a data center, in accordance with some embodiments of thepresent invention. The fabric switch includes switch 1003. The laserlight supply system 301 is optically connected to supply laser power toall transceivers 1007-1 to 1007-N in the fabric switch by way of opticalconnections 1005-1 to 1005-N. Each of the transceivers 1007-1 to 1007-Nhas an optical output through which its transmitter can transmit anoptical data stream and an optical input through which its receiver canreceive an optical data stream. The transceivers 1007-1 to 1007-N can beconnected to send and/or receive optical data streams to/from othercomponents outside of the fabric switch 1001, as indicated by opticalcommunication links 1009-1 to 1009-N.

FIG. 11 shows a number of laser light supply systems 301-1 to 301-Nplaced in a dedicated laser supply rack/cabinet 1101 in a data center,in accordance with some embodiments of the present invention. Each ofthe laser light supply systems 301-1 to 301-N can be opticallyconnected, such as through an optical conveyance device, to supply laserpower to other components within the data center. For example, laserlight supply system 301-1 is optically connected to supply laser powerto components 1105-1 to 1105-N by way of optical connections 1103-1 to1103-N, respectively, where each of components 1105-1 to 1105-N is aserver rack or fabric switch or other component within the data center.Similarly, laser light supply system 301-2 is optically connected tosupply laser power to components 1109-1 to 1109-N by way of opticalconnections 1107-1 to 1107-N, respectively, where each of components1109-1 to 1109-N is a router box or fabric switch or other componentwithin the data center. And, similarly, laser light supply systems 301-3to 301-N can be optically connected to supply laser power to componentswithin the data center by way of optical connections 1111-1 to 1111-N.Also, it should be understood that each of the laser light supplysystems 301-3 to 301-N can be configured to have essentially any numberof laser light supply outputs.

It should be understood that the embodiments shown in FIGS. 9, 10, and11, represent examples of how the laser light supply system 301 can bedeployed within a data center, and are neither exhaustive nor limitingwith regard to how the laser light supply system 301 can be deployedwithin a data center. In other embodiments, the laser light supplysystem 301 can be utilized within a data center in configurations notspecifically illustrated herein. It should be understood that the laserlight supply system 301 is configured to remotely and independentlygenerate a laser light supply of multiple wavelength continuous wavelaser light that can be optically distributed through the opticaldistribution network 307 for use by any number of components within thedata center.

FIG. 12 shows a flowchart of a method for supplying laser light forfiber-optic data communication, in accordance with some embodiments ofthe present invention. The method includes an operation 1201 forgenerating multiple wavelengths of continuous wave laser light at alocation physically separate from one or more optical transceivers thatutilize the multiple wavelengths of continuous wave laser light forencoding data. Each of the multiple wavelengths of continuous wave laserlight is available for encoding separate data into a separate data lightstream. The method also includes an operation 1203 for transmitting eachof the multiple wavelengths of continuous wave laser light in acollective and simultaneous manner through an optical distributionnetwork to the one or more optical transceivers. In various embodiments,the optical distribution network includes a network of one or moreoptical splitters and one or more optical amplifiers. The method alsoincludes an operation 1205 for receiving the multiple wavelengths ofcontinuous wave laser light at the one or more optical transceivers. Themethod also includes an operation 1207 for using one or more of themultiple wavelengths of continuous wave laser light received at the oneor more optical transceivers to encode data into one or more data lightstreams.

In some embodiments, the method includes combining the multiplewavelengths of continuous wave laser light onto an optical conveyancedevice for transmission to the optical distribution network. In someembodiments, combining the multiple wavelengths of continuous wave laserlight onto the optical conveyance device is done using an opticaladd/drop comb filter. In some embodiments, the method includes operatingthe optical add/drop comb filter to either add or drop a selectedwavelength of the multiple wavelengths of continuous wave laser lightto/from the optical conveyance device. In some embodiments, combiningthe multiple wavelengths of continuous wave laser light onto the opticalconveyance device is done using an optical coupler network. In someembodiments, the optical coupler network is configured to combine eachof the multiple wavelengths of continuous wave laser light onto each ofmultiple optical conveyance devices, such that each of the multipleoptical conveyance devices is connected to receive all of the multiplewavelengths of continuous wave laser light, with each of the multipleoptical conveyance devices optically connected to a respective one ofmultiple optical outputs of the optical coupler network.

In some embodiments, generating multiple wavelengths of continuous wavelaser light in operation 1201 includes operating multiple lasers. Eachof the multiple lasers is configured to generate a different wavelengthof continuous wave laser light. In some embodiments, the method includesdistributing a thermal flux emanating from each of the multiple lasersto maintain each of the multiple lasers at a substantially uniformtemperature, and allowing the substantially uniform temperature to varyin accordance with a distributed thermal flux emanating from each of themultiple lasers. In some of these embodiments, the multiple lasers areoperated without active temperature control, and the optical transceiveris operated in a wavelength tracking mode. In some embodiments, theoptical transceiver is configured as a DWDM transceiver.

In some embodiments, the laser light supply system 301 disclosed hereinprovides for inclusion of multiple wavelengths of laser light on each ofmultiple optical conveyance devices, and provides for distribution ofthe output laser power through the multiple optical conveyance devicesto multiple locations in a data center. Also, the laser light supplysystem 301 disclosed herein enables supply of laser power at a highwall-plug energy efficiency. Use of a high-powered multiple wavelengthlaser light generator 303 across multiple optical links reduces thetotal number of laser light sources, which in turn increases a mean timeto failure of the laser light generator 303 and enables low-overheadcontrolled redundancy of the laser light sources. It should beunderstood that the high-powered multiple wavelength laser lightgenerator 303 disclosed herein is capable of producing enough continuouswave laser power to supply multiple DWDM optical links in an opticalfiber network. In some embodiments, the laser light supply system 301disclosed herein is configured to distribute laser light to the DWDMoptical links using optical conveyance devices. The optical conveyancedevices have low loss, which enables the laser light generator 303 to beplaced far away from the transceiver modules, e.g., 311-1 to 311-N, thatmake up the optical links. In some embodiments, the optical conveyancedevices used within the laser light supply system 301 are single-modeoptical fibers.

The laser light supply system 301 disclosed herein has multipleapplications beyond supplying laser light for data center transceivers.For example, in some embodiments, the laser light supply system 301 canbe implemented to generate and supply laser light for light detectionand ranging (LIDAR) in automobiles. And, in some embodiments, the laserlight supply system 301 can be implemented to generate and supply laserlight for optical communication and sensing purposes in home, office,and/or manufacturing electronics, among others. And, in someembodiments, the laser light supply system 301 can be implemented togenerate and supply laser light for biometric and/or acoustic sensingusing optical devices as the sensing elements.

By way of example, in some automobile application, LIDAR-on-a-chip makesit possible to remove mechanical components from a LIDAR system. In someembodiments, LIDAR chips are placed in several locations on the exteriorof an automobile, so that in combination they may sense a 360 degreeradius around the automobile. For example, four LIDAR chips may beplaced on the automobile, one on each of the four corners of theautomobile. In some embodiments, these LIDAR chips can be supplied withlaser light using the laser light supply system 301 as a centralizedlaser source in combination with an optical-fiber-based lightdistribution network disposed within the automobile, in accordance withthe system and methods disclosed herein.

By way of example, in some optical communication applications in thehome, office, and/or manufacturing facility, the laser light supplysystem 301 can be used as a centralized laser light source incombination with an optical-fiber-based light distribution network toprovide laser power to multiple electronic devices. In this manner,laser power can be supplied for communicating and/or sensing purposesinside of the electronics, for the purpose of being able to communicateand sense large amounts of information, as well as for reducing theenergy usage of the electronics in the facility (home, commercialbuilding, manufacturing facility, etc.).

By way of example, in some biometric and/or acoustic sensingapplications, optical devices (in particular resonant optical devices)can leverage their sensitivity to environmental conditions to functionas sensing elements. For both biometric and acoustic based sensors,optical devices can be arrayed in large numbers in a two-dimensionalarray to gain spatial resolution. The biometric sensors primarily usethe effect of the presence of a particle on the optical index ofrefraction, and hence, the device's optical properties. Acoustic sensorsuse the mechanical deformations caused by acoustic pressure waves toinfluence the optical behavior of the device. Both biometric andacoustic based sensing systems can use the laser light supply system 301as a centralized laser source in combination with an optical-fiber-basedlight distribution network to provide laser power for use acrossmultiple sensing elements in the same array or across multiple arrays.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention. Individual elements or features ofa particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the invention, and all such modificationsare intended to be included within the scope of the invention.

Although the foregoing invention has been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications can be practiced within the scope of theappended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the described embodiments.

What is claimed is:
 1. A laser light supply system for fiber-optic datacommunication, comprising: a laser light generator including a pluralityof lasers configured to simultaneously generate a plurality ofwavelengths of continuous wave laser light, each of the plurality oflasers configured to generate a different wavelength of continuous wavelaser light relative to others of the plurality of lasers, the laserlight generator having an optical output, the laser light generatorconfigured to transmit a laser light supply through the optical output,the laser light supply including each of the plurality of wavelengths ofcontinuous wave laser light in a form that does not convey an encodingof data for subsequent decoding, the plurality of lasers thermallycoupled together without active cooling of the plurality of lasers; anoptical conveyance device connected to receive the laser light supplyfrom the optical output of the laser light generator; and an opticaldistribution network having an optical input connected to the opticalconveyance device to receive the laser light supply from the laser lightgenerator, the optical distribution network configured to transmit thelaser light supply to each of one or more optical transceivers, whereinthe laser light generator is physically separate from each of the one ormore optical transceivers.
 2. The laser light supply system as recitedin claim 1, wherein each of the plurality of lasers is mounted inthermal contact with a common thermally conductive substrate configuredto distribute heat emanating from each of the plurality of lasers. 3.The laser light supply system as recited in claim 1, wherein the laserlight generator includes a set of optical conveyance devicesrespectively corresponding to the plurality of lasers, each opticalconveyance device in the set of optical conveyance devices connected toreceive the continuous wave laser light generated by a corresponding oneof the plurality of lasers.
 4. The laser light supply system as recitedin claim 3, wherein the laser light generator includes an opticalcoupler network having a set of optical inputs respectively connected tothe set of optical conveyance devices such that the optical couplernetwork is connected to separately receive the continuous wave laserlight at the different wavelengths as generated by the plurality oflasers, the optical coupler network configured to combine the continuouswave laser light at the different wavelengths together onto each ofmultiple optical conveyance devices, such that each of the multipleoptical conveyance devices is connected to receive all of the differentwavelengths of continuous wave laser light generated by the plurality oflasers, with each of the multiple optical conveyance devices opticallyconnected to a respective one of multiple optical outputs of the opticalcoupler network.
 5. The laser light supply system as recited in claim 4,wherein the laser light generator includes multiple optical amplifiersrespectively disposed along the multiple optical conveyance devices,each of the multiple optical amplifiers configured to amplify eachwavelength of light transmitted along its corresponding one of themultiple optical conveyance devices.
 6. The laser light supply system asrecited in claim 1, wherein the optical distribution network includes anumber of optical splitters and a number of optical amplifiers connectedto amplify and transmit the laser light supply to each of the one ormore optical transceivers.
 7. The laser light supply system as recitedin claim 6, wherein the optical distribution network includessingle-mode optical fibers for transmission of the laser light supply toeach of the one or more optical transceivers.
 8. The laser light supplysystem as recited in claim 1, wherein the one or more opticaltransceivers are configured as dense wavelength division multiplexed(DWDM) transceivers.
 9. The laser light supply system as recited inclaim 8, wherein each of the one or more optical transceivers isconfigured to encode data on each of the plurality of wavelengths ofcontinuous wave laser light.
 10. The laser light supply system asrecited in claim 1, wherein each of the plurality of lasers does nothave active temperature control.
 11. The laser light supply system asrecited in claim 1, wherein each of the one or more optical transceiversis configured to track drift in the plurality of wavelengths ofcontinuous wave laser light.
 12. The laser light supply system asrecited in claim 1, wherein the plurality of lasers are thermallycoupled together in a manner that maintains a wavelength channel spacingas the plurality of wavelengths of continuous wave laser light driftwith change in temperature of the plurality of lasers.
 13. A method forsupplying laser light for fiber-optic data communication, comprising:having a laser light supply system that includes a laser lightgenerator, an optical conveyance device, and an optical distributionnetwork, the laser light generator including a plurality of lasersconfigured to simultaneously generate a plurality of wavelengths ofcontinuous wave laser light, the plurality of lasers thermally coupledtogether without active cooling of the plurality of lasers, each of theplurality of lasers configured to generate a different wavelength ofcontinuous wave laser light relative to others of the plurality oflasers, the laser light generator having an optical output, the laserlight generator configured to transmit a laser light supply through theoptical output, the laser light supply including each of the pluralityof wavelengths of continuous wave laser light in a form that does notconvey an encoding of data for subsequent decoding, the opticalconveyance device connected to receive the laser light supply from theoptical output of the laser light generator, the optical distributionnetwork having an optical input connected to the optical conveyancedevice to receive the laser light supply from the laser light generator,the optical distribution network configured to transmit the laser lightsupply to each of one or more optical transceivers, wherein the laserlight generator is physically separate from each of the one or moreoptical transceivers; operating the laser light supply system togenerate the laser light supply at a location physically separate fromeach of the one or more optical transceivers; transmitting the laserlight supply through the optical distribution network to the one or moreoptical transceivers; and allowing the plurality of wavelengths ofcontinuous wave laser light to drift with change in temperature of theplurality of lasers.
 14. The method as recited in claim 13, furthercomprising: receiving the laser light supply at any one of the one ormore optical transceivers; and using one or more of the plurality ofwavelengths of continuous wave laser light in the received laser lightsupply to generate a data light stream having encoded data defined forsubsequent decoding.
 15. The method as recited in claim 13, wherein eachof the plurality of wavelengths of continuous wave laser light isavailable for encoding separate data into a separate data light streamat any of the one or more optical transceivers.
 16. The method asrecited in claim 13, further comprising: combining the plurality ofwavelengths of continuous wave laser light onto the optical conveyancedevice for transmission to the optical distribution network.
 17. Themethod as recited in claim 16, wherein combining the plurality ofwavelengths of continuous wave laser light onto the optical conveyancedevice is done using an optical coupler network, wherein the opticalcoupler network is configured to separately receive the plurality ofwavelengths of continuous wave laser light and combine the plurality ofwavelengths of continuous wave laser light together onto the opticalconveyance device.
 18. The method as recited in claim 17, wherein theoptical coupler network is configured to combine each of the pluralityof wavelengths of continuous wave laser light onto each of multipleoptical conveyance devices, such that each of the multiple opticalconveyance devices is connected to receive all of the plurality ofwavelengths of continuous wave laser light, with each of the multipleoptical conveyance devices optically connected to a respective one ofmultiple optical outputs of the optical coupler network.
 19. The methodas recited in claim 13, wherein the optical distribution networkincludes a network of one or more optical splitters and one or moreoptical amplifiers.
 20. The method as recited in claim 13, whereinoperating the laser light supply system to generate the laser lightsupply includes operating at least two of the plurality of lasers,wherein the method further includes allowing thermal flux emanating fromeach of the operating lasers to distribute through a single thermallyconductive substrate to maintain each of the operating lasers at asubstantially uniform temperature.
 21. The method as recited in claim20, further comprising: allowing the substantially uniform temperatureto vary freely in accordance with a distributed thermal flux emanatingfrom each of the operating lasers.
 22. The method as recited in claim20, wherein the operating lasers are operated without active temperaturecontrol.
 23. The method as recited in claim 22, wherein each of the oneor more optical transceivers is operated in a wavelength tracking mode.24. The method as recited in claim 23, wherein each of the one or moreoptical transceivers is configured as a dense wavelength divisionmultiplexed (DWDM) transceiver.
 25. The method as recited in claim 24,further comprising: operating each of the one or more opticaltransceivers to encode data on each of the plurality of wavelengths ofcontinuous wave laser light.
 26. The method as recited in claim 13,further comprising: operating each of the one or more opticaltransceivers to track drift in the plurality of wavelengths ofcontinuous wave laser light.
 27. The method as recited in claim 13,further comprising: maintaining a wavelength channel spacing as theplurality of wavelengths of continuous wave laser light drift withchange in temperature of the plurality of lasers.